Split antenna for dual channel fuze

ABSTRACT

An antenna cap for a dual channel transceiver mounted in a proximity fuze comprising a segmented frusto-conical member composed of insulating material, a pair of electromagnetic excitable elements separately secured on the conical surface of said member, a point of common potential in said fuze, a conducting shield plate inserted within said material between said electromagnetic elements and electrically connected to said point of common potential, two separate transceivers operating on different frequencies and independently of each other, each of said transceivers electrically connected to a respective one of said electromagnetic elements and to said point of common potential, whereby the signal transmitted from one of the channels is isolated from the signal transmitted from the other channel.

llnited Sttes ate Packard [4 1 Apr. 17, 1973 SPLIT ANTENNA FOR DUAL CHANNEL F UZE [75] Inventor: Alden Packard, Little Rock, Ark.

[73] Assignee: The United States of America as represented by the Secretary of the Navy [22] Filed: Nov. 15, 1956 [21] App]. No.: 622,509

[52] US. Cl. ..l02/70.2 P, 343/873 [51 Int. Cl ..F42l 13/00 [58] .Field of Search ..102/70.2, 70.2 P;

[ 5 6 References Cited UNITED STATES PATENTS 2,787,788 4/1957 Clough ..343/742 1,623,996 4/1967 Caner 1. .."343/75l 2,455,403 12/ 1 948 Brown ...343/84l 2,478,313 8/1949 Peterson .343/873 2,61 1,869 9/1952 Willoughby ,.343/873 OTHER PUBLICATIONS Radio Proximity Fuze Design by Wilbur S. Hinmen,

Jr., and Cledo Brunett. Research Paper RP1723. Volume 37, July 1946, Journal of Research of the National Bureau of Standards. Pages 1-18 are pertinent.

Proximity Fuzes for Artillery by l-lainer Selvidge February 1946 issue of Electronics Magazine. Pages 7 I 104 thru 109 are pertinent.

Primary Examiner-Samuel W. Engle Att0rneyQ. E. Hodges and Q. B. Warner [5 7] ABSTRACT An antenna cap for a dual channel transceiver mounted in a proximity fuze comprising a segmented frusto-conical member composed of insulating materia1, a pair of electromagnetic excitable elements separately secured on the conical surface of said member, a point of common potential in said fuze, a conducting shield plate inserted within said material between said electromagnetic elements and electri- Cally connected to said point of common potential,

two separate transceivers operating on different frequencies and independently of each other, each of said transceivers electrically connected to a respective one of said electromagnetic elements and to said point -of common potential, whereby the signal transmitted from one of the channels is isolated from the signal transmitted from the other channel.

4 Claims, 3 Drawing Figures 7 PATENTEU' 3.727. 554

INVENTOR. ALDEN PACKARD ATTYS SPLIT ANTENNA FOR DUAL CHANNEL FUZE This invention relates to electromagnetic wave radiators and more particularly to a novel antenna unit concurrently excitable by a plurality of electromagnetic energy waves.

While the invention is readily adaptable for general use with radio frequency transceivers and the like, the invention may be used to particular advantage in radio frequency apparatus where a high degree of compactness and extreme ruggedness and strength are desired. Accordingly,-for illustrative purposes, the novel radiator unit will be described in connection with a dual channel proximity fuze for projectiles, or the like, of the type disclosed in a copending application of John D. Reid, Ser. No. 622,510 filed Nov. 15, 1956.

It has been proposed heretofore for radiating and receiving a plurality of divers electromagnetic energy signals in a multiple channel proximity fuze to couple each transceiver channel of the fuze through a frequency discriminating network and a single antenna cap to the projectile radiator. It has also been proposed in a dual channel proximity fuze to employ an antenna cap for one transceiver channel of the fuze and an uncapped wire, subjacent the antenna cap, for the other transceiver channel. Although fairly satisfactory results have been obtained with the prior art antenna arrangements, some difficulties have been experienced in the former arrangement due to the necessity for careful tuning of the networks and the comparatively low eff"- ciencies resulting from energy losses in the networks. In thelatter hereinabove recited prior art arrangement undesirable coupling, or interaction, existed between the transceiver channels due to the relatively small physical separation attainable in the limited space available in a proximity fuze.

Accordingly, one object of the present invention is to provide a new and improved antenna unit excitable by a plurality of electromagnetic waves.

Anotherobject of the present invention is to provide a new and improved electromagnetic energy radiator arrangement concurrently excitable by a plurality of divers radio-frequency signals.

A further object of the present invention is to provide a means for electrically coupling a plurality of transceiver systems contained within a body to the body.

A still further object of the present invention is to provide a new and improved segmented antenna cap excitable by a plurality of divers radio-frequency signals.

Another still further object of the present invention is to provide means for exciting a single radio-frequency radiator from a plurality of oscillators operating at divers frequencies.

Other objects and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to Referring now to the drawing wherein like reference numerals indicate like parts throughout the several views, and more particularly to FIGS. 1 and 2 whereon the antenna coupler, or cap, according to the present invention is indicated generally by the reference numeral 11. As shown thereon, the antenna coupler 11 includes a frusto-conical block 12, composed of an electrical insulating material suitable for the purpose, such for example, as polyethylene or the like, split into segmented portions 13 and 14 of comparable though not necessarily identical configuration. Arranged upon segments 13 and 14 are coupling or radiating elements 15 and 16, respectively, said elements being composed of material suitable for the purpose, such for example, as copper foil, or the like, and which may either be embedded within their respective segments or secured to the surfaces thereof by any one of many well known conventional methods. Also, the radiating elements 15 and 16 may consist of a thin metallic coating which has been sprayed upon the segments while in a molten state. Physically interposed between segments 13 and 14 of the assembled frusto-conical antenna cap is an electrical shield 17, composed of any suitable electrically conductive material, said shield being extended beyond the base 18 of the insulating block 12 for connection to an available common terminal 19 such for example as the fuze amplifier shield can 21, as more clearly shown in FIG. 3. The shield 17 serves to minimize cross-coupling and thereby provides a satisfactory degree of isolation for the transceiver oscillators 22 and 23 arranged in the intervening space 24 between the antenna coupler 11 and shield can 2.1 on opposing sides of the extended shield plate 17. As shown in FIG. I, for illustrative purposes, the oscillators 22 and 23 are inductively coupled through r.f. transformers 25 and 26, respectively, to the radiating elements 15 and 16, respectively. The electrical connection between the antenna coupling element-s and the transformers may be effected by soldering leads 27 and 28 to the elements 15 and 16 at points 29 and 31 respectively.

It is to be understood that although the frusto-conical member 12 of the antenna cap 11 according to the present invention has been described and illustrated as comprising only a pair of segments for effecting radiation of a pair of r.f. signals, that the device is not limited for use with a pair of signals, but may be readily adapted to excite a projectile radiator from a plurality of r.f. signal sources by splitting the frusto-conical member 12 into a larger number of segments with corresponding radiating elements disposed thereon and interposing shielding members between each of said segments.

In FIG. 3 an ordnance projectile 32 having an electrically conductive body of a resonant length is illustrated as having a multiple channel proximity fuze 33 employing the antenna cap 11 according to the present invention, affixed to the nose thereof for coupling the divers electromagnetic energies generated by the oscillators of the fuze 33 to the projectile body radiator. As shown thereon the intervening region 24 of the proximity fuze, wherein are disposed the fuze oscillators is filled by an insulating potting compound to provide a firm support for the oscillator circuits contained therein. A plastic front case 34, broken away for illustrative purposes encloses the proximity fuze 33.

It should be understood that the antenna cap of a proximity fuze contributes only slightly to the radiated electromagnetic field, and functions principally as a means for coupling the transceiver to the projectile body, which is the major radiator of electromagnetic energy.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An antenna cap for a dual channel transceiver mounted in a proximity fuze comprising a segmented frusto-conical member composed of insulating material; a pair of electromagnetic excitable elements separately secured on the conical surface of said member, a point of common potential in said fuze, a conducting shield plate inserted within said material between said electromagnetic elements and electrically connected to said point of common potential, two separate transceivers operating on different frequencies and independently of each other, each of said transceivers electrically connected to a respective one of said electromagnetic elements and to said point of common potential, whereby the signal transmitted from one of the channels is isolated from the signal transmitted from the other channel.

2. An antenna cap according to claim 1 wherein said segmented frusto-conical member is formed of polyethylene.

3. An antenna cap according to claim 1 wherein said electromagnetic energy excitable means comprises a metallic film.

4. Apparatus for electrically transmitting and receiving a multiple channel proximity fuze signals comprising a projectile casing, a frusto-conical member composed of insulating material and physically connected to said projectile casing, said frusto-conical member being formed of a plurality of segments corresponding to the number of channels of the multiple channel proximity fuze, a shield plate contiguously interposed between each adjacent pair of segments of said frustoconical member and being electrically connected to a point of common potential in the proximity fuze, and a conductive surface conformingly disposed upon each of said segments and electricallyconnected to an individual channel of the proximity fuze for simultaneously coupling the electromagnetic energy developed by each channel to said projectile casing thereby radiating multiple signals into space. 

1. An antenna cap for a dual channel transceiver mounted in a proximity fuze comprising a segmented frusto-conical member composed of insulating material, a pair of electromagnetic excitable elements separately secured on the conical surface of said member, a point of common potential in said fuze, a conducting shield plate inserted within said material between said electromagnetic elements and electrically connected to said point of common potential, two separate transceivers operating on different frequencies and independently of each other, each of said transceivers electrically connected to a respective one of said electromagnetic elements and to said point of common potential, whereby the signal transmitted from one of the channels is isolated from the signal transmitted from the other channel.
 2. An antenna cap according to claim 1 wherein said segmented frusto-conical member is formed of polyethylene.
 3. An antenna cap according to claim 1 wherein said electromagnetic energy excitable means comprises a metallic film.
 4. Apparatus for electrically transmitting and receiving a multiple channel proximity fuze signals comprising a projectile casing, a frusto-conical member composed of insulating material and physically connected to said projectile casing, said frusto-conical member being formed of a plurality of segments corresponding to the number of channels of the multiple channel proximity fuze, a shield plate contiguously interposed between each adjacent pair of segments of said frusto-conical member and being electrically connected to a point of common potential in the proximity fuze, and a conductive surface conformingly disposed upon each of said segments and electrically connected to an individual channel of the proximity fuze for simultaneously coupling the electromagnetic energy developed by each channel to said projectile casing thereby radiating multiple signals into space. 